Molding of annular components involves two streams of resin flowing along opposite sides of the annular mold cavity, with the front faces of the two streams coming together and forming a weld or knit line that is visible at the surface. It is known to provide an outboard gate adjacent the knit line leading to an outboard overflow cavity to try and improve the knit line. Nevertheless, the inclusion of fibrous material in the resin is known to result in significantly weaker knit lines due to improper orientation of the fibers at the knit line.
Automotive vehicles include a large number of annular components, including bezels commonly found on instrument panels, door trims, floor consoles, tail lamps, badging, etc. The surface of these components that is visible must meet Class A standards, which includes not having a visible knit line. When a Class A surface with metallic flake appearance is desired, the part must be first molded and then separately painted to provide the metal flake appearance. Despite the manufacturing inefficiency and additional costs of such separate molding and painting operations, none of the automotive manufacturers, the molding suppliers, or the metallic resin suppliers have been able to find a way to mold annular components with a metallic resin without a visible knit line at the Class A surface that eliminates the need to separately paint the Class A surface.